Results: At 2Gy, a dose dependent reduction in DNA injury was seen with VC and GL (Table). Under fluoroscopic irradiation, the control tubes without addition of any antioxidant chemicals dem- onstrated 4.15 +/- 0.16 foci of DNA repair per nucleus while the tubes enriched with 0.16 mM VC showed 3.11 +/- 0.2 foci per nucleus (a 25% reduction, p = 0.10). Oral URAC pre-medication of the blood donor for 5 days prior to drawing and radiating the blood sample at CT doses led to a foci decrease per nucleus from 9.6 +/- 4.3 to 6.4 +/- 5.9. DNA repair foci induced by gamma-irradiation in peripheral white blood cells - impact of vitamin C (VC) and glutathione (GL) Group + Control (2Gy) - Control (0 Gy) 0.02 mM VC (2Gy) 0.2 mM VC (2Gy) 3.8 mM VC (2Gy) 0.05 mM GL Foci/Nucleus- mean (SD) 16.5 (5.9) 6.6 (8.8) 11.3 (8.3) 5.5 (5.6) 3.1 (2.9) 2.9 (3.5) Conclusion: Our results suggest that antioxidant pre-medica- tion of patients prior to medical imaging exams or workers prior occupational exposure can protect DNA from radiation damage. Abstract No. 267 In vivo gene delivery using an arginine peptide delivery system (VIPER) in an orthotopic hepatocellular carcinoma rat model L.J. Higgins, G.L. Hwang, R.H. Katzenberg, N. Kothary, D.Y. Sze, L. Hofmann; Interventional Radiology, Stanford School of Medicine, Palo Alto, CA Purpose: Previously we have shown that a non-viral Vector using combinations of iopamidol (I, iodinated contrast agent), protamine (P), and ethiodized oil (E)-VIPER-selectively transfect hepatoma cells. We hypothesized that intratumoral delivery to an orthotopic hepatocellular carcinoma (HCC) rat model would result in significant gene expression compared to a commercially avail- able (although not clinically translatable) cationic lipid (Altogen). Materials and Methods: Firefly luciferase plasmid DNA (F- Luc) was used as a reporter gene for gene delivery to a previously described orthotopic HCC Rat Model using hepatoma cells (McARH7777). In vivo transfection efficiency was measured us- ing a bioluminescence imaging CCD-camera. VIPER “cocktail” combinations optimized in vitro were used for intra-tumoral in- jection and compared to a cationic lipid (positive control) and naked DNA (negative control). Results: VIPER condition, 20:1 P:DNA, 8% E, 33% I, proved to have better transfection efficiency when compared to 5O:1 P:DNA, 2% E, and 4% E combinations. The control cationic lipid proved to be 1.2–1.7x better than VIPER. Representative data includes VIPER (20:1 P:DNA, 8% E, 33% I; n=3) 1.7x10^5 p/sec/cm^2/sr, VIPER (50:1 P:DNA, 2% E, 33% I; n=3) 1.2x10^5 p/sec/cm^2/sr, VIPER (100:1 P:DNA, 4% E, 33% I; n=3) 7.3x10^4, Altogen;n=4 2.13x10^5 p/sec/cm^2/sr. Conclusion: We have shown that the in vitro optimized VIPER combinations of ethiodized oil, protamine, iopamidol and DNA are translatable to in vivo gene delivery in an HCC rat model. Furthermore, transfection efficiency is comparable to a cationic lipid vector, albeit slightly less effective. In contrast to viral and cationic lipid vectors, VIPER (components of which are all FDA- approved) lends itself to iterative therapy and therefore a more easily translatable gene delivery strategy. Reference 1. M.A. van den Bosch, L.J. Higgins, G. Hwang, R.H. Katzenberg, J.K. Willmann, R. 2. Paulmurugan, W.T. Kuo, N. Kothary, S.Y. Dan, S.S. Gamb- hir, L.V. Hofmann. Journal of Vascular and Interventional Radiology. February 2008 (Vol. 19, Issue 2, Pages S136 –S137). Abstract No. 268 Developing a VX2 rabbit head and neck tumor model D. Wong, E.W. Lee, V. Prieto, C. Tran, C.T. Loh, S.T. Kee; Div of Interventional Radiology, Department of Radiology, UCLA Medical Center, Los Angeles, CA Purpose: As the incidence of head and neck cancers continue to rise, the development of an animal tumor model which is anatom- ically and pathophysiologically sufficient to allow imaging and novel treatments would be an attractive option for interventional radiologist seeking to study head and neck cancers. Therefore, the purpose of this study is to develop a suitable VX2 rabbit head and neck tumor model to be utilized in interventional oncologic re- search and treatments. Materials and Methods: Upon ARC approval, fourteen New Zealand White rabbits (n=14) were implanted with a minced tumor volume of 0.2 – 0.3 mL subcutaneously into the lower third of right auricle using a 20-gauge angiocatheter.. Based on our experience with VX2 liver model, the tumor was allowed to grow for one week to reach a size of approximately 1 cm and was further monitored and evaluated up to 3 weeks. The tumor growth was evaluated with both US and CECT imaging immediately, 1 wk, 2 wks and 3 wks post-implantation. The immunohistological assessment of these tumors was performed. Results: VX2 tumors were implanted and grown successfully in all 14 rabbits. An average size of VX2 neck tumor at 1 wk was 9.5  2.4 mm. In 3 wks, the VX2 tumor demonstrated metastasis to the cervical lymph nodes. The CECT validated the location and tumor characteristics of the VX2 tumor in the pos- terior-auricular region/muscle (in the region of proximal sterno- cleidomastoid muscle) in all 14 rabbits. The immunohistological analysis demonstrated markedly proliferative (Ki-67 positive) mesenchymal cells. Conclusion: We were able to successfully validate and create a VX2 rabbit head and neck tumor model using both radiological and immunohistological analysis. With this success, this model may be a suitable platform for interventional radiologists or sur- gical oncologists searching for an animal model for head and neck cancer research. Educational Exhibit Abstract No. 269 Initial experience using a new interventional CT navigation tool (Activiews) for percutaneous CT guided ablation and biopsy T. Cabrera, L.N. Boucher, D.A. Valenti; Radiology, McGill University, Montreal, QC, Canada Learning Objectives: To demonstrate the advantages of an innovative system to improve CT guided lesion targetting. S114 Poster Sessions  JVIR Poster Sessions